2-Step rev limit at WOT

[panamarojo]

I seem to be hitting a rev limiter at 5500 rpms during WOT. My 2-step is setup at 5500 rpms on a new chip I just got. I had the clutch wire to ecu mod for a different chip still hooked up, could that cause a problem?

 

[ArmyGSX]

If the ECU is not seeing the clutch switch then it will think your sitting still and use the launch limit as a rpm limiter.

My friends 90 talon has a disconnected clutch switch and has his launch limit set to 7000 so he can use it as a rev limit.

 

[panamarojo]

I removed the wire and disconnected clutch switch so I can start the car without holding the clutch down.

I am still having the problem I even turned down boost to 10lbs. It boost nice in all gears till it hits 5500rpm. Then there is a rev limiter. How does the chip know when the car is not at a stop and when the car is stopped so that the 2-step kicks in? I would think it gets a signal from vehicle speed sensor? But wouldn't my rpm gauge or speedometer not work?

Thanks for the help.

 

[urmomsaniceguy]

Check the speed limit. It deactivates when you reach above that speed.

 

[panamarojo]

How do I check this? What speed?

 

[GsxEcutioner]

Broken speed sensor?

 

[steve]

Depending on who wrote the code the launch limiter will check the input from the speed sensor, clutch switch, or both. The VSS on a 1G is built into the speedometer, a cable drives the speedometer from the trans and there is a little reed switch that opens and closes to produce the VSS signal. It's brought out to the OBD1 connector pin 10 so you can check it with a voltmeter. When the car is moving the voltage should pulse between 5v and ground.

 

[panamarojo]

It's from Chicago DSM. Ill get more info on it here soon. I will test it at the DTC. Would a data logger help? Wouldn't there be other issues also if the VSS went out?

So if it's the yellow/white wire at the DLC. I have found out that it hops from 0 to 5 at the very beginning. It was staying between 1.5-2 volts jumping around and sometimes staying steady. At idle it's a steady 4.5 or higher.

http://www.dsmtuners.com/forums/newbie-forum/384567-diagnostic-port-wire-color.html

 

[steve]

The only things that use the VSS are the cruise control and the automatic trans. MMCD can look at the ECU counter that is decremented by the VSS if you give it the right address.

It's hard to read the pulses once the car starts moving since a voltmeter will average the voltage unless your meter will display frequency. Sounds like your getting something from the VSS.


What does the chip say on it?

 

[panamarojo]

I would figure I could see the pulse at very low speeds. I will run the test again tomorrow. I noticed 12.2 volts at fuel pump during idle, I will be doing the re wire mod tomorrow. I will also try out original eprom once zif socket gets here.

It's for a 2g maf, 680cc injectors, 18* timing, 7500 rev limit, and 5500 launch.

Is there anything on the SAFC wiring to the ECU that could cause this if the wiring came loose? I will double check those also. Is there a write up on settings the address on the palm MMCD to see the VSS?

Also I have a fluke 87 I will check the manual to see if it says anything about frequency display for voltage.

 

[spooling 1g]

Check your speedo cable,i forgot mine after my clutch installed and was hitting my 2 step while driving.

 

[panamarojo]

Wouldn't my speedometer not work if it was the speedometer cable? I will be testing to see if there is continuity running back to the ecu from the DTC connection.

 

[stukyl28]

Could the chip be messed up were it is limiting your launch and rev limit to 5500? You said you just got it that sounds like a big indicator right there... Just my .02 cents

 

[panamarojo]

That is a possibility but I would like to make sure it's nothing up with me car.

 

[Archer Fabrications]

Check the speed limit. It deactivates when you reach above that speed.

+1

if you are running DSMlink go into live access then RPM and you will see launch rev limit and then you will see "disable launch at or above (blank or what ever rpm you have)... with this said, the rev limiter will be activated until you reach or exceed what ever MPH you have it set for.

 

[panamarojo]

I had a bad connection at the ECU when I reversed the clutch wire mod. Fixed with a better connector. I must have ruined the connector trying to crimp it under the dash, not too much room under there. Everything is perfect now. Thanks.

 

[Archer Fabrications]

thread to be closed after resolved?

 

[steve]

thread to be closed after resolved?

Not usually! They typically stay open unless somebody breaks the rules and forces them to be closed.

 

[MY1GDSM]

The Op should mark the thread as resolved though....